This patch adds the 'ip' match extension to ebtables-compat.
It involves adapting old ebtables extension code to the xtables-compat
environment.
For testing:
% sudo ebtables-compat -p 0x0800 --ip-src 1.1.1.1 -j ACCEPT
The patch includes a cached copy of the extension kernel header.
Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@xxxxxxxxx>
---
extensions/libebt_ip.c | 326 +++++++++++++++++++++++++++++++
include/linux/netfilter_bridge/ebt_ip.h | 44 ++++
iptables/xtables-eb.c | 1
3 files changed, 371 insertions(+)
create mode 100644 extensions/libebt_ip.c
create mode 100644 include/linux/netfilter_bridge/ebt_ip.h
diff --git a/extensions/libebt_ip.c b/extensions/libebt_ip.c
new file mode 100644
index 0000000..ffb7ed6
--- /dev/null
+++ b/extensions/libebt_ip.c
@@ -0,0 +1,326 @@
+/* ebt_ip
+ *
+ * Authors:
+ * Bart De Schuymer <bdschuym@xxxxxxxxxx>
+ *
+ * Changes:
+ * added ip-sport and ip-dport; parsing of port arguments is
+ * based on code from iptables-1.2.7a
+ * Innominate Security Technologies AG <mhopf@xxxxxxxxxxxxxx>
+ * September, 2002
+ *
+ * Adapted by Arturo Borrero Gonzalez <arturo.borrero.glez@xxxxxxxxx>
+ * to use libxtables for ebtables-compat in 2015.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+#include <netdb.h>
+#include <xtables.h>
+#include <linux/netfilter_bridge/ebt_ip.h>
+
+#define IP_SOURCE '1'
+#define IP_DEST '2'
+#define IP_EBT_TOS '3' /* include/bits/in.h seems to already define IP_TOS */
+#define IP_PROTO '4'
+#define IP_SPORT '5'
+#define IP_DPORT '6'
+
+static const struct option brip_opts[] = {
+ { .name = "ip-source", .has_arg = true, .val = IP_SOURCE },
+ { .name = "ip-src", .has_arg = true, .val = IP_SOURCE },
+ { .name = "ip-destination", .has_arg = true, .val = IP_DEST },
+ { .name = "ip-dst", .has_arg = true, .val = IP_DEST },
+ { .name = "ip-tos", .has_arg = true, .val = IP_EBT_TOS },
+ { .name = "ip-protocol", .has_arg = true, .val = IP_PROTO },
+ { .name = "ip-proto", .has_arg = true, .val = IP_PROTO },
+ { .name = "ip-source-port", .has_arg = true, .val = IP_SPORT },
+ { .name = "ip-sport", .has_arg = true, .val = IP_SPORT },
+ { .name = "ip-destination-port",.has_arg = true, .val = IP_DPORT },
+ { .name = "ip-dport", .has_arg = true, .val = IP_DPORT },
+ XT_GETOPT_TABLEEND,
+};
+
+static void brip_print_help(void)
+{
+ printf(
+"ip options:\n"
+"--ip-src [!] address[/mask]: ip source specification\n"
+"--ip-dst [!] address[/mask]: ip destination specification\n"
+"--ip-tos [!] tos : ip tos specification\n"
+"--ip-proto [!] protocol : ip protocol specification\n"
+"--ip-sport [!] port[:port] : tcp/udp source port or port range\n"
+"--ip-dport [!] port[:port] : tcp/udp destination port or port range\n");
+}
+
+static void brip_init(struct xt_entry_match *match)
+{
+ struct ebt_ip_info *info = (struct ebt_ip_info *)match->data;
+
+ info->invflags = 0;
+ info->bitmask = 0;
+}
+
+static void
+parse_port_range(const char *protocol, const char *portstring, uint16_t *ports)
+{
+ char *buffer;
+ char *cp;
+
+ buffer = strdup(portstring);
+ if ((cp = strchr(buffer, ':')) == NULL)
+ ports[0] = ports[1] = xtables_parse_port(buffer, NULL);
+ else {
+ *cp = '\0';
+ cp++;
+
+ ports[0] = buffer[0] ? xtables_parse_port(buffer, NULL) : 0;
+ ports[1] = cp[0] ? xtables_parse_port(cp, NULL) : 0xFFFF;
+
+ if (ports[0] > ports[1])
+ xtables_error(PARAMETER_PROBLEM,
+ "invalid portrange (min > max)");
+ }
+ free(buffer);
+}
+
+/* original code from ebtables: useful_functions.c */
+static int undot_ip(char *ip, unsigned char *ip2)
+{
+ char *p, *q, *end;
+ long int onebyte;
+ int i;
+ char buf[20];
+
+ strncpy(buf, ip, sizeof(buf) - 1);
+
+ p = buf;
+ for (i = 0; i < 3; i++) {
+ if ((q = strchr(p, '.')) == NULL)
+ return -1;
+ *q = '\0';
+ onebyte = strtol(p, &end, 10);
+ if (*end != '\0' || onebyte > 255 || onebyte < 0)
+ return -1;
+ ip2[i] = (unsigned char)onebyte;
+ p = q + 1;
+ }
+
+ onebyte = strtol(p, &end, 10);
+ if (*end != '\0' || onebyte > 255 || onebyte < 0)
+ return -1;
+ ip2[3] = (unsigned char)onebyte;
+
+ return 0;
+}
+
+static int ip_mask(char *mask, unsigned char *mask2)
+{
+ char *end;
+ long int bits;
+ uint32_t mask22;
+
+ if (undot_ip(mask, mask2)) {
+ /* not the /a.b.c.e format, maybe the /x format */
+ bits = strtol(mask, &end, 10);
+ if (*end != '\0' || bits > 32 || bits < 0)
+ return -1;
+ if (bits != 0) {
+ mask22 = htonl(0xFFFFFFFF << (32 - bits));
+ memcpy(mask2, &mask22, 4);
+ } else {
+ mask22 = 0xFFFFFFFF;
+ memcpy(mask2, &mask22, 4);
+ }
+ }
+ return 0;
+}
+
+static void ebt_parse_ip_address(char *address, uint32_t *addr, uint32_t *msk)
+{
+ char *p;
+
+ /* first the mask */
+ if ((p = strrchr(address, '/')) != NULL) {
+ *p = '\0';
+ if (ip_mask(p + 1, (unsigned char *)msk)) {
+ xtables_error(PARAMETER_PROBLEM,
+ "Problem with the IP mask '%s'", p + 1);
+ return;
+ }
+ } else
+ *msk = 0xFFFFFFFF;
+
+ if (undot_ip(address, (unsigned char *)addr)) {
+ xtables_error(PARAMETER_PROBLEM,
+ "Problem with the IP address '%s'", address);
+ return;
+ }
+ *addr = *addr & *msk;
+}
+
+static int
+brip_parse(int c, char **argv, int invert, unsigned int *flags,
+ const void *entry, struct xt_entry_match **match)
+{
+ struct ebt_ip_info *info = (struct ebt_ip_info *)(*match)->data;
+
+ switch (c) {
+ case IP_SOURCE:
+ if (invert)
+ info->invflags |= EBT_IP_SOURCE;
+ ebt_parse_ip_address(optarg, &info->saddr, &info->smsk);
+ info->bitmask |= EBT_IP_SOURCE;
+ break;
+ case IP_DEST:
+ if (invert)
+ info->invflags |= EBT_IP_DEST;
+ ebt_parse_ip_address(optarg, &info->daddr, &info->dmsk);
+ info->bitmask |= EBT_IP_DEST;
+ break;
+ case IP_SPORT:
+ if (invert)
+ info->invflags |= EBT_IP_SPORT;
+ parse_port_range(NULL, optarg, info->sport);
+ info->bitmask |= EBT_IP_SPORT;
+ break;
+ case IP_DPORT:
+ if (invert)
+ info->invflags |= EBT_IP_DPORT;
+ parse_port_range(NULL, optarg, info->dport);
+ info->bitmask |= EBT_IP_DPORT;
+ break;
+ case IP_EBT_TOS:
+ if (invert)
+ info->invflags |= EBT_IP_TOS;
+ if (!xtables_strtoul(optarg, NULL, (uintmax_t *)&info->tos,
+ 0, 255))
+ xtables_error(PARAMETER_PROBLEM,
+ "Problem with specified IP tos");
+ info->bitmask |= EBT_IP_TOS;
+ break;
+ case IP_PROTO:
+ if (invert)
+ info->invflags |= EBT_IP_PROTO;
+ info->protocol = xtables_parse_protocol(optarg);
+ if (info->protocol == -1)
+ xtables_error(PARAMETER_PROBLEM,
+ "Unknown specified IP protocol - %s",
+ optarg);
+ info->bitmask |= EBT_IP_PROTO;
+ break;
+ default:
+ return 0;
+ }
+ return 1;
+}
+
+static void brip_final_check(unsigned int flags)
+{
+/* struct ebt_ip_info *ipinfo = (struct ebt_ip_info *)match->data;
+
+ if (entry->ethproto != ETH_P_IP || entry->invflags & EBT_IPROTO) {
+ ebt_print_error("For IP filtering the protocol must be "
+ "specified as IPv4");
+ } else if (info->bitmask & (EBT_IP_SPORT|EBT_IP_DPORT) &&
+ (!(info->bitmask & EBT_IP_PROTO) ||
+ info->invflags & EBT_IP_PROTO ||
+ (info->protocol!=IPPROTO_TCP &&
+ info->protocol!=IPPROTO_UDP &&
+ info->protocol!=IPPROTO_SCTP &&
+ info->protocol!=IPPROTO_DCCP)))
+ ebt_print_error("For port filtering the IP protocol must be "
+ "either 6 (tcp), 17 (udp), 33 (dccp) or "
+ "132 (sctp)");
+*/
+ if (!flags)
+ xtables_error(PARAMETER_PROBLEM,
+ "You must specify proper arguments");
+}
+
+static void print_port_range(uint16_t *ports)
+{
+ if (ports[0] == ports[1])
+ printf("%d ", ports[0]);
+ else
+ printf("%d:%d ", ports[0], ports[1]);
+}
+
+static void brip_print(const void *ip, const struct xt_entry_match *match,
+ int numeric)
+{
+ struct ebt_ip_info *info = (struct ebt_ip_info *)match->data;
+ struct in_addr *addrp, *maskp;
+
+ if (info->bitmask & EBT_IP_SOURCE) {
+ printf("--ip-src ");
+ if (info->invflags & EBT_IP_SOURCE)
+ printf("! ");
+ addrp = (struct in_addr *)&info->saddr;
+ maskp = (struct in_addr *)&info->smsk;
+ printf("%s%s ", xtables_ipaddr_to_numeric(addrp),
+ xtables_ipmask_to_numeric(maskp));
+ }
+ if (info->bitmask & EBT_IP_DEST) {
+ printf("--ip-dst ");
+ if (info->invflags & EBT_IP_DEST)
+ printf("! ");
+ addrp = (struct in_addr *)&info->daddr;
+ maskp = (struct in_addr *)&info->dmsk;
+ printf("%s%s ", xtables_ipaddr_to_numeric(addrp),
+ xtables_ipmask_to_numeric(maskp));
+ }
+ if (info->bitmask & EBT_IP_TOS) {
+ printf("--ip-tos ");
+ if (info->invflags & EBT_IP_TOS)
+ printf("! ");
+ printf("0x%02X ", info->tos);
+ }
+ if (info->bitmask & EBT_IP_PROTO) {
+ struct protoent *pe;
+
+ printf("--ip-proto ");
+ if (info->invflags & EBT_IP_PROTO)
+ printf("! ");
+ pe = getprotobynumber(info->protocol);
+ if (pe == NULL) {
+ printf("%d ", info->protocol);
+ } else {
+ printf("%s ", pe->p_name);
+ }
+ }
+ if (info->bitmask & EBT_IP_SPORT) {
+ printf("--ip-sport ");
+ if (info->invflags & EBT_IP_SPORT)
+ printf("! ");
+ print_port_range(info->sport);
+ }
+ if (info->bitmask & EBT_IP_DPORT) {
+ printf("--ip-dport ");
+ if (info->invflags & EBT_IP_DPORT)
+ printf("! ");
+ print_port_range(info->dport);
+ }
+}
+
+static struct xtables_match brip_match = {
+ .name = "ip",
+ .revision = 0,
+ .version = XTABLES_VERSION,
+ .family = NFPROTO_BRIDGE,
+ .size = XT_ALIGN(sizeof(struct ebt_ip_info)),
+ .userspacesize = XT_ALIGN(sizeof(struct ebt_ip_info)),
+ .init = brip_init,
+ .help = brip_print_help,
+ .parse = brip_parse,
+ .final_check = brip_final_check,
+ .print = brip_print,
+ .extra_opts = brip_opts,
+};
+
+void _init(void)
+{
+ xtables_register_match(&brip_match);
+}
diff --git a/include/linux/netfilter_bridge/ebt_ip.h b/include/linux/netfilter_bridge/ebt_ip.h
new file mode 100644
index 0000000..c4bbc41
--- /dev/null
+++ b/include/linux/netfilter_bridge/ebt_ip.h
@@ -0,0 +1,44 @@
+/*
+ * ebt_ip
+ *
+ * Authors:
+ * Bart De Schuymer <bart.de.schuymer@xxxxxxxxxx>
+ *
+ * April, 2002
+ *
+ * Changes:
+ * added ip-sport and ip-dport
+ * Innominate Security Technologies AG <mhopf@xxxxxxxxxxxxxx>
+ * September, 2002
+ */
+
+#ifndef __LINUX_BRIDGE_EBT_IP_H
+#define __LINUX_BRIDGE_EBT_IP_H
+
+#include <linux/types.h>
+
+#define EBT_IP_SOURCE 0x01
+#define EBT_IP_DEST 0x02
+#define EBT_IP_TOS 0x04
+#define EBT_IP_PROTO 0x08
+#define EBT_IP_SPORT 0x10
+#define EBT_IP_DPORT 0x20
+#define EBT_IP_MASK (EBT_IP_SOURCE | EBT_IP_DEST | EBT_IP_TOS | EBT_IP_PROTO |\
+ EBT_IP_SPORT | EBT_IP_DPORT )
+#define EBT_IP_MATCH "ip"
+
+/* the same values are used for the invflags */
+struct ebt_ip_info {
+ __be32 saddr;
+ __be32 daddr;
+ __be32 smsk;
+ __be32 dmsk;
+ __u8 tos;
+ __u8 protocol;
+ __u8 bitmask;
+ __u8 invflags;
+ __u16 sport[2];
+ __u16 dport[2];
+};
+
+#endif
diff --git a/iptables/xtables-eb.c b/iptables/xtables-eb.c
index a078679..27a1c16 100644
--- a/iptables/xtables-eb.c
+++ b/iptables/xtables-eb.c
@@ -639,6 +639,7 @@ static void ebt_load_matches(void)
{
opts = ebt_original_options;
ebt_load_match("802_3");
+ ebt_load_match("ip");
}
static void ebt_add_match(struct xtables_match *m,
--
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